Heretofore, piles have been utilized to bear the weight of buildings, machinery, and other structures and devices. The piles are generally tubular and they are often fluted at a uniform depth from top to bottom for the purpose of increasing their resistance to collapsing during driving but not for the purpose of permitting radial expansion. The piles also have pointed driving tips attached to the bottom thereof so that they can be driven into the earth by a pile driver. Piles are generally constructed so that as they are driven into the earth, additional piles can be connected to the top of the preceding pile and welded thereto. Any number of piles can be connected and driven into the earth until they meet an unyielding strata, such as bedrock. However, in a majority of situations, bedrock is not encountered and the piles are driven until a desirable resistance from the friction of the penetrated strata, plus the resistance encountered from the driving point, yields a desirable load-bearing capacity. Once in place, the uppermost pile is normally cutoff at a desirable height, the piles filled with concrete, and subsequently incorporated into a foundation.
A variation of the above procedure is to fill the lowermost portion of the bottom pile with concrete. A heavy weight is then dropped through the piles with the resulting impact hopefully causing the lowermost pile portion to expand horizontally outward. At best, this procedure is very tenuous and does not yield repeatable results.